The first internship, want to arrive early, but because of other reasons delayed, to the 9 o'clock like to the company, I thought to be criticized a meal, fortunately, the reception master is more friendly, directly to the grouping of the place I brought. We this time a *** came 9 people, to be divided into different groups, a group generally with 1 to 2 people, so it is easier to communicate.
It didn't take long for the person in charge to come, and after a brief introduction, we were divided into groups, and my group leader was Zhang Qinghai. He was very kind and always kept a smile on his face.
Because the first day just to report, so did not go to the base station, they are prepared to take me to see the next day.
When we arrived at the group, Mr. Zhang gave us some basic knowledge of the base station. Base station is a station in the transmission of communications, as for the specific how to wait until tomorrow I know. If the signal can be transmitted to set up a lot of sites, but the site may have some faults, thus affecting the transmission of the signal, we are dealing with the fault. So the site is monitored by the monitoring center 24 hours a day, when the monitoring center found that there is a problem, we must immediately go to the station to find out what the problem, and then notify the appropriate departments to go to the maintenance.
Internship Log Day 2 August 1, 2008
Nothing happened today, so the team leader took us on an inspection. Every month each group has to inspect all their stations once, whether there is a problem or not they have to go. The inspection is to count the models, quantities, and specifications of the equipment in the base station. Fill out the form in the base station, so that the future inspection time to use, today is the first day of August, naturally began to clean up all the sites once again.
Going into the base station, the temperature inside is 23 or 24. it's especially cool to go in during the summer, and there's a lot of equipment inside. Generally divided into the following systems: transmission system, including SDH equipment, fiber optic cables, cables, etc.; power system, batteries, utilities, etc.; dynamic ring monitoring system; antenna feeder system; BTS main equipment; as well as other auxiliary equipment, such as air conditioning, security gates and so on. The temperature inside is kept at 23℃ or 24℃. Because it is summer, it is especially cool inside, but some air conditioners are broken, and the temperature inside can reach over 40℃. Because it is an inspection so especially simple.
The so-called inspection is the name, type, number and model of all the equipment in the base station to do a statistics. The first time I saw this, I was able to see the whole thing, and I was able to see the whole thing, and I was able to see it. We have four people in this group, two drivers, but also jurisdiction over about 50 sites. Base station in my understanding should be a signal transmission of a mid-point, just as the bus station, with it you can easily to all places, and with the base station signal can be transmitted farther and wider.
Because of the first day of inspection, so there is no fault problems, we went in just to the inside of the equipment type, number of statistics, and then placed in the base station to complete the day's work. The first day of the year is the first day of the year of the first year of the second year.
Internship Log Day 3 August 2, 2008
Today was a very rewarding day in general, because the problem finally came out. 。。。。 Oh well, something to do.
In the morning, the monitoring center called to say that the base station in Tumu Village has been in serious trouble. So our team immediately set off to the village of Tumu. To there found housing outside the AC transformer is open, take me to the colleague said to himself "I clearly remember I left when he turned off ah, is someone stealing electricity?". I remember turning it off when I left, is someone stealing power? I had no idea why he was asking. He went up to fix it, and I wondered if that's what we do. And then I realized that I was completely wrong.
Then we went in and looked at the following, and he checked a couple of devices and found that they were all fine, and the air conditioner in there was running fine. That was strange. Then the driver master came in and he said to us, "I asked the people here and the power has been out here since last night." My coworker then didn't say anything. Then we called it a day.
In the car I asked him what the fault was. He said it was a power outage, and we didn't have a generator with us today, and it wasn't very important here, so let's just check it again when we have power. If we had brought a generator, we probably would have had to be here to guard the power and pull the wires. It seems to be very hard to do the maintenance of the base station.
Internship Log Day 4 August 3, 2008
Today is the day that the Olympic torch will be passed to Chengdu, haha, comfortable, because we have to go to the Panda Park to take care of the base station there, to ensure that there will be no communication problems during the torch relay.
Because we need to work to go, so into the Panda Park do not have to give tickets, hehehe, go in the Dragon and I look at the base station in Master Zhang's "guidance" directly to stroll the Panda Park, said we came once is not easy.
To 6:00 pm when the torch finished, we successfully completed the task ~ ~ hard two masters pull
In fact, this task is very important, the Olympic Games, the country is very important, and we do communication is to cause a high degree of attention. Because if the communication is interrupted, the consequences can be very serious. So before the torch came, the higher-ups have already made arrangements. The site is also divided into several categories, some important sites have to enter the field, that is, to move there to live, to ensure that the communication is unimpeded. So when I arrived at the company, there were actually people who were already living in the heavyweight sites. And our internship is not so heavy pressure, it is easy to pass ~ ~
Internship Log 7th Day August 6, 2008
Today to the base station system is RBS883, the original after the installation of the tune-up, the base station can work normally. After running for some time, the switching side test found that the tenth carrier frequency of cell B in the system had no transmit power, and after observing the scene, we found that its corresponding COMB could not be tuned.
First of all, replace the COMB, the problem remains, proving that the COMB is normal; the power meter will be connected to the TX port of the TRM, and the power of the TRM will be turned on with the LCTRL1 software, and it is found that the power meter has a power display, which proves that the TRM of the channel disk is normal; in general, if the power monitoring unit or the directional coupler is bad, it will lead to the problem of all the carriers in this cell and it should not be a certain carrier frequency. Therefore, we can conclude that the power monitoring unit and the directional coupler have no problem.
So we will focus on the connection: and the adjacent carrier frequency (eighth or twelfth carrier frequency) at the same time the COMB end of the replacement of the Pi output header and the motor connected to the carrier frequency can work normally, while the adjacent carrier frequency can not work, so that the obstacles to locate in the Pi output line and the motor connecting line; replacement of power synthesizers from the Pi port to the power monitoring unit on the COMB port of the connection line, the carrier frequency works normally, but the adjacent carrier frequency can not work, thus positioning the obstacles in the Pi output line and motor connection line; replacement from the power synthesizer on the Pi port to power monitoring unit on the COMB port between After replacing the wires from the Pi port on the power synthesizer to the COMB port on the power monitoring unit, the carrier frequency works normally and the problem is solved.
These problems are due to the damage of the wires between the Pi port of the power synthesizer and the COMB port of the power monitoring unit, the power monitoring unit is unable to receive the -32dB RF signal coupled from the power synthesizer, and thus is unable to control the COMB tuning.
Internship Log Day 8 August 7, 2008
Today's base station is using the RBS200 system. A carrier frequency does not work: the switching side of the test response is that the set of carrier frequency reception is normal but can not effectively transmit; to the base station to observe that the set of carrier frequency in the push service process, RRX, TRXC and SPU everything is normal, but RTX can not be effectively locked, resulting in the whole set of carriers can not work properly.
RBS200 generally use the form of auto-tuning synthesizer. The auto-tuning synthesizer is essentially a narrow-band combiner whose inputs are mechanically tuned to a specified GSM frequency. At the input of each combiner there is a stepper motor which is controlled by the RTX to which it is connected. the two inputs are combined to form a single output, and the outputs of a number of synthesizers can be connected in a chain. During tuning, the transmitter sets the inputs of its combiner to give the maximum forward power and also checks the power reflected back, if the reflected power exceeds the maximum allowed then the transmitter disables itself and issues an error code.
We checked and replaced the hardware devices COMB, RTX and TXD, and when we checked the RTX, we found that the pin in the "PT" port of the RTX was crooked, which prevented the RTX from making effective contact with the RF line coming from the TXD, and the RTX could not receive the reference signal from the TXD, and could not analyze and compare it with its own transmitter signal. The RTX cannot analyze and compare the signal with its own transmit signal, and thus cannot control the auto-tuning synthesizer to accurately tune to the corresponding frequency point, so the carrier frequency cannot work normally. After correcting the pin in the "PT" port of the RTX, the carrier works normally.
Day 10 August 9, 2008
There is not much to do today, so let's talk about hardware-induced alarms at base stations. One of the base stations was installed and tuned by the engineering bureau, and the base station worked normally. However, after a period of time, the traffic statistics analysis found that the A and B cells of this base station have high congestion and dropped calls. Through the BSC observation, it was found that there were diversity reception alarms in cells A and B of the station, and at the same time, there were also alarms in cell A in terms of VSWR. When observed by OMT at the base station, it was found that there were diversity reception loss alarms and VSWR/POWER detection loss alarms.
Since the alarms are related to the antenna system, we first use the VSWR tester to test the four antenna lines in cell A and B, and found that the measured values are within the standard range, proving that there is no problem with the antenna lines themselves. We know that diversity reception is one of the important measures to solve signal fading and improve signal reception strength. The cell receives signals through two receiving antennas, which can produce a gain of about 3dB, and at the same time determine whether the receiving system is normal by comparing the two signals. If the TRU detects a large difference in the strength of the two signals, the BTS will generate a diversity reception loss alarm. The diversity reception loss alarm may be caused by a failure of the TRU, the CDU, the RF link to the TRU, or the antenna feeder.
In this fault detection, we noticed that cells A and B have diversity reception alarms and high congestion and dropped calls, so we suspect that the antenna feeder lines of cells A and B are misaligned with each other. After the aerial operators checked the antenna feeders one by one, we found that the receiving antennas of cells A and B were misaligned with each other. As a result, the two receiving antennas of cell A and B are not in the same direction, and the antennas in the wrong direction cannot receive the signals from the cell phone or receive weak signals, which results in diversity reception loss alarms and high congestion and dropped calls in the cell. After the change, the diversity reception loss alarm disappeared, and the congestion and dropped calls were reduced to within the target range.
Internship Log Day 11 August 10, 2008
A channel at the base station that we inspected today failed and went out of service. The monitoring terminal showed that the channel was "MALF", and the self-diagnostic information of the system from the management terminal showed that the status of the channel was: ?DIAG? 8?11?54 ．． ?03 MA 00 TIB 22 075 c 00 21
? Time Date System Activation Master Device Device Name Device Number Status Report Target Information)
First of all, the frequency and power measurement of the channel machine, found that the frequency meets the target requirements, the power is only about 10W, after repair, I learned that the final amplifier of the fourth power tube is damaged, after replacing the power to meet the standard. But after accessing the system, the channel machine still can not enter the service state, and the diagnostic information remains the same. Measure its frequency and power again, the two values are in line with the target requirements. Analyze the working frequency of the channel may be interfered with, after sweeping the frequency is indeed the existence of an interference source, remove the source of interference after the channel machine to restore normal service state.
Interference is an important factor in limiting the performance and capacity of wireless communication systems, which can cause crosstalk, call loss or call signal dropout and prevent users from obtaining satisfactory call quality, and most importantly, it restricts the tightness of the reusable frequencies available to operators. Interference may originate from another mobile terminal, from other wireless communication devices operating on the same frequency, or from out-of-band RF energy leaking into the allocated spectrum. The most usual types of cluster interference are co-channel interference and adjacent channel interference. After the interference phenomenon, the source of the interference and the cause of the interference should be identified as soon as possible, so that the damage caused by the interference can be minimized as much as possible.
Although the MOTOROLA SMARTNET Ⅱ system is a set of high degree of intelligence, strong reliability of the trunked communication system, but in the actual operation of all kinds of faults, in order to ensure smooth communication, especially to ensure that the important departments of the smooth flow of communication scheduling, we need to comprehensively grasp the performance of the system, and in the process of day-to-day maintenance to constantly summarize the lessons learned, and strive to improve the system maintenance level. The company's website has been updated with the latest information on the system.
Internship log twelfth day August 11, 2008
Today is the last day of the internship, was looking forward to doing something again. It turned out that our base station security system is doing quite well, which is a good thing, huh? Master Zhang and the driver took us out to inspect two base stations, wander around and come back to write a couple of reports. In the company apartment where we rested we talked a lot, about learning, about the Olympics, about the work of BTS maintenance, and much, much more. In the past 10 days, we got along very well with Mr. Zhang and his team, and it's really hard to leave now, especially with the air-conditioned emergency vehicle, hehehe. But there is no such thing as an unending banquet, when we leave, we can only thank them again and again for giving us careful teaching, patient explanation, especially the dear Zhang Qinghai master.
2:00 pm we left the apartment, are very reluctant, may they work well.
We left the apartment at 2pm.